TURBULENT SHEAR-STRESS EFFECT ON MAMMALIAN-CELL CULTURE AND MEASUREMENT USING LASER-DOPPLER ANEMOMETER

The effect of turbulent shear stress on a suspension cell line (KG-1) derived from human erythrocytic leukemia has been studied. The previou s studies in the area of shear and animal cells have not been able to provide a quantitative measure of the turbulent shear stress in a stir red bioreactor and correlate the shear forces to the damage of animal cells. The present study bridges that crucial gap and provides a quant itative estimate of the turbulent shear stress existing in the commonl y used spinner flask system. The cells were sheared under turbulent co nditions by using a magnetic bar at agitation speeds of 2.5, 5 and 7.5 r/s in a spinner flask. The parameters used to estimate cell damage w ere the total and viable cell count of the population, the proliferati ng ability and the cytoskeletal structure of the treated cells. The tu rbulent shear stress experienced by the cells was quantitatively estim ated by using a laser Doppler anemometer. The agitation of cells in th e presence and absence of fetal bovine serum at a lower agitation spee d of 2.5 r/s demonstrated the shear protective effect of serum. The me asurement of turbulent stresses in medium with and without serum indic ated that serum caused a reduction in the turbulent stresses, thus pro viding an insight into its protective mechanism.